Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2014
ABSTRACT: Orbital transfer missions require a demanding combination of lightweight, flexible operation and high Thrust-to-Power (greater than 120 mN/kW) electric propulsion. Adding Neutral Entrainment (NE) to a pulsed electromagnetic thruster has the potential to dramatically increases the total Thrust-to-Power by decreasing effective plasma frozen flow and ionization losses. It also enables a new class of thrusters, so-called Combustion Enhanced Electric Propulsion. In Combustion Enhanced EP a lightweight propellant in burned in a micro mono-propellant thruster within an EP system. That decomposed, hot, neutral gas is then entrained in a 5-15 kW class NE thruster. This coaxial combination of thrusters decreases overall system mass and complexity, while simultaneously increasing performance. By harnessing the momentum and chemical energy of the mono-propellant and entraining it in a plasma stream, T/P can be increased at all operational exhaust velocities. The following Phase I study will develop a series of system and thermo-chemical models to optimize total efficiency, T/P, and system flexibility. An experimental program will address the thermal and engineering challenges of a Combustion Enhanced Electric Propulsion system. BENEFIT: By utilizing Combustion Enhanced Electric Propulsion with an electromagnetic thruster, lightweight mono-propellants can be used from 200-2000 s specific impulse. This thruster system will greater than 100 mN/kW and operate over 50% efficiency from 500 to 2000 s. Additionally, this system should be lightweight (less than 1 kW/kg). These combined abilities yield a thruster system that has numerous mission benefits and, thus, commercial benefits. A 3-15 kW system operating on a green mono-propellant would enable wide-ranging multi-mode orbital transfer missions. For non-DOD missions, the ability to efficiently use In-Situ Resources has tremendous benefits to interplanetary missions.
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase I | Award Amount: 149.00K | Year: 2010
A new thruster technology, the Electrodeless Lorentz Force (ELF) thruster, has been designed and tested at MSNW that has the capability to address the demanding combined requirements of high specific power, high efficiency, a large Isp range, and T/P in a single, lightweight device. The ELF thruster creates a high-density, magnetized plasma known as a Field Reversed Configuration using Rotating Magnetic Field formation. Coupled with an applied bias field gradient, the resulting JxB force accelerates the propellant to high velocity. The program goal of the ELF research was to characterize a thruster concept possessing the potential to surpass all current electric propulsion systems in efficiency, power, and operational variability. Based on current laboratory results, ELF would enable a range of high-power propulsion missions in the 10-100 kW class. The ELF thruster technology has been demonstrated to have a wide range of specific impulse (1,000-6,000) at high efficiency and operate on many propellants. Additionally, its pulsed nature inherently enables dramatic (expected up to 1000:1) power throttling while maintaining the optimal specific impulse, efficiency, and operational conditions. Proposed is a program to design, test, and optimize a highly-throttleable, full-scale 30-50 kW ELF thruster operating in a steady-state configuration.
Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase II | Award Amount: 749.62K | Year: 2014
ABSTRACT: State of the art Orbital Transfer Vehicle systems and GEO transfer missions require the demanding combined requirements of both high Thrust-to-Power (greater than 150 mN/kW) and high specific impulse (greater than 3000 s), all at constant power. The 9 kW PROTEAN system is a two-stage plasmoid thruster which adds secondary Neutral Entrainment (NE) to the ElectroMagnetic Plasmoid Thruster (EMPT) to dramatically increases the total Thrust-to-Power. This NE stage injects neutral propellant into the plasma path, which are accelerated to high velocity through resonant charge exchange collisions. The NE stage then highly efficiently adds kinetic energy to the engorged plasmoid through Peristaltic Dynamic Acceleration, in which sequenced magnetic coils provide a large magnetic pressure gradient. In total, this system allows for very efficient acceleration of a plasmoid as well as the addition of active propellant mass, all without significant further ionization or plasma frozen flow losses. By simply varying the secondary propellant input flow rate, thrust and specific impulse can be dynamically varied at constant input power and without affecting the initial plasma formation. PROTEAN is therefore a thruster system with less than 5 eV/ion plasma frozen flow losses and can provide mission designers an almost infinitely variable Isp and thrust range. BENEFIT: The PROTEAN thruster system will be able to provide greater than 150 mN/kW and operate from 800-5000 s specific impulse. Additionally, this system will be lightweight (a specific power of greater than 1 kW/kg) and be able to operate at constant power across a wide range of specific impulse conditions. This thruster will have the ability to operate with lower than 5 eV/ion, dramatically less than any Electric Propulsion system in existence. These combined abilities yield a thruster system that has numerous mission benefits and, thus, commercial benefits. The 9 kW PROTEAN operating on Xenon would enable wide-ranging Orbital Transfer Vehicles and GEO/GTO orbit raising missions. A PROTEAN system operating on lightweight or chemically reactive gases would truly allow for high thrust-to-power multi-mode operation. For non-DOD missions, the ability to efficiently use In-Situ Resources has tremendous benefits to interplanetary missions.
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase II | Award Amount: 1.12M | Year: 2011
The Electromagnetic Plasmoid Thruster (EMPT) has demonstrated the ability to ionize, electromagnetically accelerate, and eject a broad range of complex and chemically-reactive molecular gases, including monopropellants. EMPT has the potential to dramatically increase the operational range of existing electric propulsion (EP) systems in both power density, power throttling, and propellant choice. Proposed here is a Phase II program to develop protoflight hardware for the EMPT thruster to be flown on FalconSAT-6. This experiment will demonstrate the in-space operation of a high specific power pulsed thruster operating at 1 kW average power on Xenon. A ground-based multi-mode development will demonstrate the electromagnetic operation of the EMPT on monopropellants. The highly scalable EMPT represents a dramatic advancement for EP technology and has direct applications for 1 kW to 1 MW EP thrusters